I feel for you, brother. I don't have much advice to offer, but I will point out that when it comes to being thrown into water, your gun doesn't have to be your only excuse. Many of us carry expensive electronics devices everywhere we go, and a $400 cell phone or $600 PDA + water = instant death. ( Death for the expensive electronics, that is.) Not to mention wallet, receipts, personal notes, shoes, belt, clothing, any variety of things that could be ruined by a dunk, and we're rapidly approaching property values that constitute a felony.
My family and friends don't have to know that I'm carrying a gun to know that trying to toss me into the pool would result in someone getting a face-plant on the concrete. I'm an easy-going, fun-loving guy, but I don't horseplay. And because some people caught up in the spirit of fun can be clue-resistant, I wouldn't hesitate to penetrate their clue-shields by being loud, harsh, profane, and threatening.
Do what you have to do to get their attention and make them stop. Apologies and misunderstandings can be worked out later.
Kevin